Regulatory mechanisms for apoptosis in placental tissue during normal pregnancy and gestosis-complicated pregnancy.

The localization of apoptosis and expression of proapoptotic and antiapoptotic factors by the placental tissue were compared during normal pregnancy and gestosis-complicated pregnancy. The degree of apoptosis did not differ in the third trimester of normal pregnancy and gestosis-complicated pregnancy. Increased expression of Fas, caspase-8, and caspase-3 in placental tissue during normal pregnancy was shown to contribute to the suppression of angiogenesis and growth of placental tissue. No differences were found in the expression of FasL (CD95L), caspase-2, caspase-9, and Mcl-1 by placental cells during normal pregnancy and gestosis-complicated pregnancy. Increased expression of TRAIL by trophoblast cells is a protective mechanism from apoptotic signals of maternal cytotoxic lymphocytes and NK cells during gestosis.